I remember S&H Green stamps, but growing up in Washington DC we collected Top Value stamps. I even remember the jingle:

Get Top Value stamps where you shop!
Get Top Value stamps where you buy!
Get Top Value gifts for the stamps that you save
Get Top Value stamps (they're just like gold!)
and save! save! save!

and then a voice would come on and say, in a fake Scottish brogue, "They're thrrrrrrifty!"

Don